JPH04291010A - Production of thin-film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a thin-film magnetic head which is free from the fluctuation in the accuracy of the gap depth of the thin-film magnetic head by controlling the work strains of the floating surface and rear surface of a head block. CONSTITUTION:The work strains of the floating surface and rear surface of the head block are controlled by deforming the head block 1 and fixing and polishing the head block or by using polishing methods of different work strains so as to offset the work strains of the floating surface and the rear surface at the time of fixing the head block 1 to a jig for dealing with working of a gap depth.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin film magnetic head, and more particularly to a method for manufacturing a thin film magnetic head from a head block on which a plurality of thin film magnetic heads are mounted.

0002

2. Description of the Related Art Conventionally, a method for manufacturing a thin film magnetic head from a head block equipped with a plurality of thin film magnetic heads is described in Japanese Patent Application Laid-Open No. 64-76418. This was done by making the amount of grinding, that is, the amount of processing substantially the same, and grinding both sides, thereby equalizing the processing stress on both sides of the head block and improving the linearity of the arrangement of the thin-film magnetic heads. .

0003

During the manufacture of thin film magnetic heads, the thickness of the head block has become thinner due to the trend towards miniaturization of thin film magnetic heads. As a result, the rigidity of the head block during processing is reduced, and the linearity of the arrangement of the thin film magnetic heads is greatly degraded due to deformation of the head block. The conventional technique has a problem in that the gap depth accuracy, which influences the performance of the thin-film magnetic head, varies greatly within the head block. The main causes of this are variations in processing strain on both sides of the head block and adhesive strain when bonding to a jig.

[0004] The purpose of the present invention is to control processing distortion on both sides,
It is an object of the present invention to provide a method for manufacturing a thin film magnetic head without variations in gap depth accuracy of the thin film magnetic head.

[0005]

[Means for Solving the Problems] In order to achieve the above object, in a method for manufacturing a thin film magnetic head in which a head block on which a plurality of thin film magnetic heads are mounted is processed to a predetermined gap depth dimension, gap depth dimension processing is provided. Before this, a step is added to intentionally change the machining strain on the air bearing surface side and the back surface side of the head block, thereby changing the arrangement of the thin film magnetic heads in the head block to an optimal arrangement.

[0006]

[Operation] According to the present invention, when a thin film magnetic head formed in the shape of a substrate is cut into head blocks and processed into a desired shape, a processed strain layer (
An internal residual stress layer (internal residual stress layer) is generated due to machining, and the head block is in a balanced state depending on the size relationship. If the machining strain on either side (the flying surface or the back surface) of the head block in this balanced state is changed, the previous balanced state is canceled, the block is deformed, and after the deformation, a new balanced state is achieved. This machining strain has a certain correlation with the machining method, and by selecting this machining method, it becomes possible to control the machining strain and arbitrarily control the deformation of the head block.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

To manufacture a thin film magnetic head, first, a ceramic substrate on which a large number of thin film magnetic heads having thin film magnetic head elements 7 are formed is cut into head blocks 1 on which a plurality of thin film magnetic heads are mounted. FIG. 1 is a schematic diagram of the head block 1. Next, the back surface side 1b and the air bearing surface side 1a of the head block 1 are ground until the desired thickness is obtained, and then, as shown in FIG. 2, the head block 1 is bonded to a jig 3 for machining the gap depth dimension.

When the deformation during adhesion is such that the air bearing surface side 1a is concave, the head block 1 is deformed in a convex direction toward the air bearing surface side 1a by an amount that offsets the deformation due to adhesion, and the head The linearity of the line 4 of the thin film magnetic head elements in the block 1 was maintained.

Furthermore, as shown in FIG. 3, the deformation of the air bearing surface side 1a in the convex direction is caused by compressive stress occurring on the air bearing surface 1a and back surface 1b of the head block because the processing strain layer is a compressive stress layer. A force as shown by arrow 5 is generated. Therefore, if the process-strained layer on the back surface is removed by low-strain processing (for example, ion milling or etching), the compressive stress on the air bearing surface side 1a will become relatively large depending on the amount removed, and the air bearing surface side 1a will become convex. Deformation is caused by the same amount as in the concave direction.

[0011] As another method, relatively back side 1
In an example carried out by the inventor, as a method for reducing the machining strain of b, as shown in FIG.
By machining with coarse abrasive grains compared to the machining abrasive grains b, the machining strain on the air bearing surface side 1a relative to the back surface side 1b is increased, and the air bearing surface side 1a is deformed to the same extent in the convex direction, and the amount of deformation is could also be controlled.

By using the method described above, the linearity of the alignment line of the thin film magnetic head in the head block before gap depth dimensioning is improved, and by polishing the air bearing surface parallel to the alignment line, the precision can be improved. Gap depth machining with little variation is possible. Furthermore, by improving the gap depth accuracy, it is possible to improve the bending of conventional thin-film magnetic heads, which occurs to the same extent as the gap depth crossing before polishing the air bearing surface.

[0013]

According to the present invention, the amount of bending of the array of thin film magnetic heads during processing can be reduced to almost zero.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a thin-film magnetic head block according to an embodiment of the present invention.

[Figure 2] Cross-sectional view of the thin-film magnetic head block and jig shown in Figure 1 when bonded together

[Fig. 3] Schematic diagram of processing a thin film magnetic head block according to an embodiment of the present invention.

FIG. 4 Schematic diagram of processing a thin film magnetic head block according to another embodiment of the present invention.

[Explanation of symbols]

1...Head block 1a...Head block air bearing surface 1b…Back side of head block 2...Adhesive 3...Jig 4... Thin film magnetic head alignment line 5...Force caused by compressive stress 6…Amount of processed strain layer removed 7... Thin film magnetic head element

Claims (5)

[Claims] 1. A substrate on which a plurality of thin film magnetic head elements are formed is cut into blocks, the air bearing surface side and the back surface side of the block are ground until the block has a desired thickness, and then the air bearing surface side is ground. In a manufacturing method for thin-film magnetic heads in which the magnetic head is polished to a predetermined gap depth, the gap depth can be processed by controlling the processing strain on the air bearing surface side and the back side of the head block before gap depth processing. A method for manufacturing a thin-film magnetic head, comprising controlling the amount of deformation of the block during the process. 2. The method of manufacturing a thin film magnetic head according to claim 1, wherein when fixing the head block to a gap depth machining jig, machining strain on the air bearing surface and the back surface cancel each other out. A method of manufacturing a thin film magnetic head, which comprises deforming a head block, fixing it, and polishing it. 3. The method of manufacturing a thin film magnetic head according to claim 1, wherein the air bearing surface and back surface of the head block are subjected to lapping processing using abrasive grains before the gap depth processing. Head manufacturing method. 4. In the method for manufacturing a thin film magnetic head according to claim 3, the surface roughness of the back surface of the thin film head is 0.3.
A thin film head characterized in that the Rmax is less than μmRmax. 5. A method for manufacturing a thin film magnetic head according to claim 1, wherein the head block is processed by adding ion milling to reduce processing distortion.